Microeconomics for Business

In game theory, a dominant strategy is a strategy that gives a player a higher payoff than any other strategy, whatever strategy the rival player chooses. A player with a dominant strategy will always play it, regardless of the opponent's choice.

Example (two firms, advertising): payoffs in profit (Firm A, Firm B):

For A: if B advertises, 10 > 5; if B does not, 15 > 8. So "advertise" is A's dominant strategy. By symmetry it is also B's. The outcome is (advertise, advertise) with (10, 10), though both would be better off at (8, 8) by not advertising. This is the prisoners' dilemma.

When every player has a dominant strategy, the outcome is a dominant strategy equilibrium (a special case of Nash equilibrium). Many games, however, have no dominant strategy.

Indifference curve: An indifference curve is a curve showing all combinations of two goods that give a consumer the same level of satisfaction (utility). The consumer is indifferent among the combinations on one curve. Its slope is the marginal rate of substitution:

$MRS_{XY}=-\frac{\Delta Y}{\Delta X}=\frac{MU_X}{MU_Y}$

Properties: downward sloping, convex to the origin (diminishing MRS), do not intersect, and higher curves represent higher satisfaction.

Assumptions: consumer is rational, preferences are consistent and transitive, utility is ordinal, more goods are preferred to less, and income and prices are given.

Budget line: with income $M$ and prices $P_X, P_Y$:

$P_XX+P_YY=M$

Its slope is $-P_X/P_Y$. Every point on it is affordable.

Consumer equilibrium: The consumer wants to reach the highest indifference curve attainable with the budget. Equilibrium is at the point where the budget line is tangent to an indifference curve.

Conditions:

1. First-order: slope of the indifference curve equals the slope of the budget line:

$MRS_{XY}=\frac{MU_X}{MU_Y}=\frac{P_X}{P_Y}$

2. Second-order: the indifference curve is convex to the origin at the equilibrium point (MRS diminishing).

Explanation: Points on a lower curve are affordable but give less satisfaction. Points on a higher curve, beyond the budget line, are unaffordable. At the tangency point E the consumer buys $X^*$ of X and $Y^*$ of Y. At any other point on the budget line, the consumer would be on a lower indifference curve. For instance if $MRS>P_X/P_Y$, the consumer values X more than the market does, so buys more X and less Y until equality holds.

Thus the consumer maximises satisfaction when $MU_X/P_X=MU_Y/P_Y$, which matches the cardinal utility equilibrium condition.

A firm is in equilibrium (profit maximising) where $MR=MC$.

$1200-25Q=200+25Q$

$1000=50Q\ \Rightarrow\ Q=20$

The equilibrium quantity is 20 units. (Second-order condition: slope of MC, $25$, is greater than slope of MR, $-25$, so profit is maximised.)

Profit is maximised where $MR = MC$:

$1000 - 20Q = 100 + 10Q$

$900 = 30Q \Rightarrow Q = 30$

The equilibrium quantity is 30 units. The second-order condition holds because the slope of MC (10) exceeds the slope of MR (-20).

1. Scarcity and choice: Resources are limited while wants are unlimited, so people must choose and every choice involves an opportunity cost.
2. Rational decision at the margin: People compare marginal benefit with marginal cost, and act only if the benefit is at least as great as the cost.

Demand is a flow concept because it is always expressed per unit of time, such as 50 kg of rice per week or 200 litres of milk per month. A quantity demanded with no time period has no meaning, just as income is a flow measured over a period.

Total utility (TU) is the sum of the marginal utilities of all units consumed. When MU falls but is still positive, each additional unit still adds something to TU, though the addition is smaller than before. So TU keeps rising, but at a decreasing rate. TU reaches its maximum when MU becomes zero.

Features of a monopoly market:

• A single seller of the product, so the firm is the industry.
• No close substitutes for the product.
• Strong barriers to entry (legal, patent, control of resources, scale).
• The firm is a price maker with control over price or output.
• Price discrimination is possible, and the demand curve is downward sloping.

Accounting profit is total revenue minus explicit (actual money) costs only, such as wages, rent and raw materials.

Economic profit is total revenue minus both explicit and implicit costs (such as the owner's own labour and capital, i.e. opportunity costs). Economic profit is therefore lower than accounting profit.

The marginal rate of technical substitution is the ratio of the marginal productivities of the two inputs:

$MRTS_{LK}=\frac{MP_L}{MP_K}=2$

So the ratio of marginal productivities $MP_L : MP_K = 2 : 1$. The marginal product of labour is twice that of capital, i.e. one unit of labour can replace two units of capital without changing output.

Given $P_1=20,\ P_2=16,\ Q_1=100,\ Q_2=120$.

$\%\Delta Q=\frac{120-100}{100}\times100=20\%,\qquad \%\Delta P=\frac{16-20}{20}\times100=-20\%$

$E_d=\frac{\%\Delta Q}{\%\Delta P}=\frac{20}{-20}=-1$

So $|E_d|=1$: demand is unitary elastic.

Given $Q=50L^3K^2$ with $L=2$ and $K=10$.

$Q=50\times2^3\times10^2=50\times8\times100=40{,}000$

The firm's output is 40,000 units.

Business economics (managerial economics) applies economic theory and tools to business decision making. Its scope covers:

1. Demand analysis and forecasting: studying determinants of demand, elasticity and forecasting future sales, which guide production and inventory plans.
2. Production and cost analysis: production functions, returns to scale, cost behaviour and cost minimisation help in choosing the best input combination and output level.
3. Pricing decisions: price determination under different market structures (perfect competition, monopoly, oligopoly) and pricing policies and strategies.
4. Profit management: profit measurement, break-even analysis and planning to deal with uncertainty and risk in profit.
5. Capital budgeting and investment decisions: evaluating long-term investment projects and the cost of capital.
6. Market structure and competition analysis: understanding rivals' behaviour and choosing strategies, including game-theory ideas.
7. Macroeconomic environment: national income, inflation, business cycles, trade, monetary and fiscal policies, and government regulation, which form the environment of business.
8. Resource allocation: using scarce resources efficiently among alternative uses to meet objectives.

Thus business economics bridges economic theory and business practice, and its scope spans both micro and macro issues relevant to a firm.

Monopolistic competition has many sellers selling differentiated products, with free entry and exit. Each firm faces a downward-sloping, fairly elastic demand curve.

Short run: a firm produces where $MR=MC$ and may earn supernormal profit (or a loss).

Long-run equilibrium:

• Supernormal profit attracts new firms. Entry shares the market, so each firm's demand (AR) curve shifts leftward and becomes more elastic. Losses cause exit and the opposite shift.
• Adjustment continues until the demand curve (AR) is tangent to the long-run average cost (LAC) curve. At that point price equals average cost, so only normal profit is earned and there is no incentive to enter or leave.

Conditions at equilibrium:

$MR=LMC\quad\text{and}\quad P=AR=LAC$

Output $Q^*$ is where $LMC$ cuts $MR$ from below. Price $P^*$ is read from the demand curve at $Q^*$, and equals LAC there.

Features of the outcome:

• Price exceeds marginal cost ($P>MC$) because of product differentiation.
• Tangency occurs on the falling part of LAC, so the firm produces less than the minimum-LAC output. The gap is called excess capacity.
• Firms earn only normal profit in the long run.

In the diagram, AR (demand) touches LAC at the point corresponding to $Q^*$ and $P^*$, and MR cuts LMC vertically below that point.

Isoquant: An isoquant (equal product curve) is a curve showing all the different combinations of two inputs (such as labour and capital) that yield the same level of output. For example, 100 units may be produced by 5L + 2K, 3L + 3K or 2L + 5K.

Properties:

1. Downward sloping: to keep output constant, more of one input requires less of the other. The slope is the MRTS.
2. Convex to the origin: because the marginal rate of technical substitution diminishes as labour replaces capital.
3. Do not intersect: two isoquants crossing would imply the same input combination gives two different outputs, which is contradictory.
4. Higher isoquant means higher output: curves farther from the origin represent more inputs and a larger quantity of output.
5. Do not touch either axis: because both inputs are needed to produce the good (except in the case of perfect substitutes).
6. Need not be parallel or have the same shape: the substitution rate differs across output levels.

Isoquants, together with isocost lines, are used to find the least-cost input combination.

Average cost (AC) is total cost per unit, $AC=TC/Q$. Marginal cost (MC) is the addition to total cost from producing one more unit, $MC=\Delta TC/\Delta Q$. Both curves are U-shaped.

Relationship:

1. When MC < AC, AC falls. The extra unit costs less than the average, pulling the average down.
2. When MC > AC, AC rises. The extra unit costs more than the average, pulling it up.
3. When MC = AC, AC is at its minimum and is neither rising nor falling. So the MC curve cuts the AC curve from below at the lowest point of AC.
4. MC reaches its minimum earlier than AC (MC rises first because of diminishing returns), so MC lies below AC in the early range.
5. Both rise ultimately due to the law of variable proportions.

The same relationship holds between MC and AVC: MC cuts AVC at its minimum point.

Numerical example: if AC of 4 units is Rs 10 and the 5th unit has MC = Rs 6, new AC = (40+6)/5 = Rs 9.2 (falls). If MC = Rs 20, new AC = Rs 12 (rises).

Given $P=200-2Q$ and $C=Q^2+40Q+2$.

$TR=PQ=200Q-2Q^2\ \Rightarrow\ MR=200-4Q$

$MC=\frac{dC}{dQ}=2Q+40$

Profit-maximising condition $MR=MC$:

$200-4Q=2Q+40\ \Rightarrow\ 6Q=160\ \Rightarrow\ Q=\frac{80}{3}\approx26.67$

(Second-order condition: $d^2\pi/dQ^2=-4-2=-6<0$, so profit is maximum.)

Price:

$P=200-2\left(\tfrac{80}{3}\right)=\tfrac{440}{3}\approx\text{Rs }146.67$

$TR=\tfrac{440}{3}\times\tfrac{80}{3}=\tfrac{35200}{9}\approx3911.11$

$C=\left(\tfrac{80}{3}\right)^2+40\left(\tfrac{80}{3}\right)+2=711.11+1066.67+2=1779.78$

$\pi=TR-C=3911.11-1779.78\approx\text{Rs }2131.33$

Profit-maximising output is about 26.67 units and maximum profit is about Rs 2,131.33.

The supply curve of labour shows the quantity of labour workers are willing to offer at different wage rates. A shift of the curve (not a movement along it) is caused by factors other than the wage:

1. Population and labour force size: growth in population, migration and a higher participation rate shift supply right.
2. Education, skills and training: better-qualified workers increase the supply of labour for skilled jobs.
3. Non-wage conditions of the job: better working conditions, job security, benefits and shorter hours raise supply; poor conditions reduce it.
4. Wages in alternative occupations: if wages in other jobs rise, labour moves away and supply in this occupation shifts left.
5. Preference for leisure and social attitudes: attitudes toward women working, retirement age and work culture alter supply.
6. Government policy: taxes, minimum age, unemployment benefits, labour laws and immigration rules.
7. Remittance and foreign employment: in Nepal, outward migration for foreign employment reduces domestic labour supply.
8. Non-labour income and wealth: higher unearned income may reduce the willingness to work.

Factors raising labour supply shift the curve to the right; those reducing it shift it to the left.

Microeconomics: Microeconomics is the branch of economics that studies the economic behaviour of individual units such as consumers, households, firms and industries. It deals with how prices of goods and factors are determined, how resources are allocated among alternative uses, and how consumers and producers make decisions. Because it works through the price mechanism, it is also called price theory.

Main areas: theory of consumer behaviour and demand, theory of production and cost, theory of the firm and market structures, theory of factor pricing (rent, wage, interest, profit), and welfare economics.

Uses in business operations:

1. Demand analysis and forecasting: elasticity and demand theory help firms estimate sales and plan production.
2. Production decisions: production functions, isoquants and returns to scale guide the selection of the best input mix and scale of output.
3. Cost analysis: cost curves help in cost control and finding the output level with lowest unit cost.
4. Pricing decisions: knowledge of market structure helps set price and output under competition, monopoly or oligopoly.
5. Profit maximisation: the $MR=MC$ rule determines the optimum output and profit.
6. Resource allocation: helps managers allocate scarce resources efficiently among competing uses.
7. Factor pricing: guides decisions about wages, rent, interest and profit.
8. Strategic decisions: game theory and oligopoly models help firms respond to competitors.
9. Government policy evaluation: helps firms understand the effect of taxes, subsidies and price controls.

Hence microeconomics provides the analytical tools by which business managers take rational decisions under scarcity.

Given $TC=200+5Q-0.04Q^2+0.001Q^3$.

(a) Total fixed cost is the part that does not vary with output:

$TFC=200$

$AFC=\frac{TFC}{Q}=\frac{200}{10}=20\ \text{at }Q=10$

(b) $TVC=5Q-0.04Q^2+0.001Q^3$

$AVC=\frac{TVC}{Q}=5-0.04Q+0.001Q^2$

$AC=\frac{TC}{Q}=\frac{200}{Q}+5-0.04Q+0.001Q^2$

$MC=\frac{dTC}{dQ}=5-0.08Q+0.003Q^2$

(c) At $Q=10$:

$AVC=5-0.4+0.1=4.7$

$AC=20+4.7=24.7$

$TC=200+50-4+1=247$

$MC=5-0.8+0.3=4.5$

Check: $AC\times Q=24.7\times10=247=TC$. (The question lists AVC twice; the fourth value intended is MC, given above.)

Price elasticity of supply: $E_s=\dfrac{\%\Delta Q}{\%\Delta P}$.

(a) Proportional (percentage) method

B to D: $P:200\to400$, $Q:2000\to4000$.

$\%\Delta Q=\frac{2000}{2000}\times100=100\%,\quad \%\Delta P=\frac{200}{200}\times100=100\%$

$E_s=\frac{100}{100}=1$

D to B: $P:400\to200$, $Q:4000\to2000$.

$\%\Delta Q=\frac{-2000}{4000}\times100=-50\%,\quad \%\Delta P=\frac{-200}{400}\times100=-50\%$

$E_s=\frac{-50}{-50}=1$

(b) Arc method

$E_s=\frac{\Delta Q}{\Delta P}\times\frac{P_1+P_2}{Q_1+Q_2}$

C to E: $P:300\to500$, $Q:3000\to5000$.

$E_s=\frac{2000}{200}\times\frac{300+500}{3000+5000}=10\times\frac{800}{8000}=1$

E to C: $P:500\to300$, $Q:5000\to3000$.

$E_s=\frac{-2000}{-200}\times\frac{800}{8000}=10\times0.1=1$

In every case $E_s=1$: supply is unitary elastic. Because the supply schedule is a straight line through the origin, elasticity is 1 throughout, and the arc method gives the same value in both directions, while the proportional method would differ in other schedules depending on the base chosen.

(a) Causes of rising prices

1. Fall in supply: the transport strike and blockade at the Indian border stopped loaded vehicles carrying essentials from entering Nepal, so supply in the local market fell. With demand unchanged, the supply curve shifted left and prices rose (potato, onion, cauliflower, French bean, fruits).
2. Dependence on imports: uncertainty of import from India, especially for potatoes and onions (dry onion rose by Rs 50 per kg).
3. Low domestic supply: even domestic vegetables (parwal, barela, up Rs 15 each) rose because the protest disrupted movement and marketing.
4. Inelastic demand: essential goods are needed regardless of price, so demand falls little and prices jump.
5. Panic buying and hoarding: expectations of further shortage raise demand and encourage traders to hold stock.
6. Perishability and storage constraints: limited storage means supply cannot be quickly adjusted.

Fish rose from Rs 225 to Rs 315 (Rs 100 rise as stated) and its quantity demanded fell from 85,000 kg to 72,000 kg, i.e. a fall of about 15.3% against a price rise of about 44%.

(b) Factors affecting demand and supply

Demand: price of the good, prices of substitutes and complements, consumer income, tastes and preferences (e.g. health awareness), population, season and festivals, and expectations about future prices.

Supply: price of the good, input costs (seeds, fertiliser, labour, fuel), technology and irrigation, weather and season, transport and storage facilities, government taxes/subsidies, number of sellers, expectations, and political stability or strikes.

(c) Elasticity and price fluctuation

Yes, I agree. Price fluctuation is strongly influenced by elasticities of demand and supply:

• Demand for vegetables is inelastic (necessities, few substitutes, small share of income), so a small change in supply causes a large change in price.
• Supply of agricultural goods is inelastic in the short run (perishable, crop cycle is long, storage is limited), so quantity cannot adjust quickly to price changes.
• When both are inelastic, any shift in supply or demand causes wide price swings, as in the case: a transport shock raised potato, onion and bean prices sharply, while earlier gluts made prices fall.
• Goods with more elastic demand, such as some fruits (pineapple, pomegranate), show a larger quantity response; fish demand fell about 15% when price rose about 44%, an elasticity of about 0.34 (inelastic).

(d) Price control measures

1. Price ceiling (maximum price) on essential items to protect consumers.
2. Price floor (support price) for farmers when prices fall during gluts.
3. Buffer stock: buy during surplus and release during shortage through Food Management Company or cooperatives.
4. Subsidised sales through public outlets and cooperatives.
5. Import facilitation: diversify import sources, remove transport blockades, and ensure supply routes.
6. Anti-hoarding and market monitoring: act against black-marketing and set up a market monitoring team.
7. Storage facilities: cold storage and collection centres to reduce perishability.
8. Rationing in severe shortages.
9. Promote domestic production to reduce import dependence.

Microeconomics studies the behaviour of individual consumers, firms and markets. It helps business decisions by explaining demand and its elasticity (pricing), costs and production (input mix and output level), market structure (competition and strategy), and profit-maximising rules such as $MR = MC$. It therefore guides what to produce, how much, at what price and with which inputs.

Market efficiency is the condition in which resources are allocated so that the total surplus (consumer surplus plus producer surplus) is maximised. In a perfectly competitive market, equilibrium occurs where price equals marginal cost, so no one can be made better off without making someone else worse off (Pareto efficiency).

The price effect is the total change in the quantity demanded of a good when its price changes, with income and other prices held constant. In indifference-curve analysis it is the movement from one equilibrium to another along the price-consumption curve. It consists of the substitution effect plus the income effect.

In perfect competition, there is free entry and exit. If firms earn supernormal profit, new firms enter, supply increases and price falls until profit disappears. If firms make losses, firms exit, supply falls and price rises. In the long run, price settles at the minimum point of average cost ($P = AC = MC$), so each firm earns only normal profit.

Penetration pricing is a pricing strategy in which a firm sets a low initial price for a new product to enter the market quickly, attract many customers and gain market share. Once the market is established, the price may be raised. It is effective when demand is elastic and there is a threat of competitors.

Capital is a man-made factor of production, such as machinery, buildings, tools and equipment, that is used to produce other goods and services rather than consumed directly. In the money sense, it also means funds invested in a business. Its reward is interest.

Quantity falls by 30% while total revenue rises by 15%, so price must have risen by more than the quantity fell:

$1.15 = (1+\Delta P)(1-0.30) \Rightarrow 1+\Delta P = 1.643 \Rightarrow \Delta P \approx 64.3\%$

$E_d = \frac{30}{64.3} \approx 0.47$

Since $|E_d| < 1$, the demand is inelastic. This agrees with the rule that a price rise increases total revenue when demand is inelastic.

A profit-maximising firm hires labour until wage equals the marginal revenue product:

$W = MRP_L = MP_L \times P = 1500 \times 5 = \text{Rs } 7{,}500$

The firm will pay a wage of Rs 7,500 per month per labourer.

This statement combines two of the principles of economics.

Markets are usually a good way to organize economic activity

• In a market economy, decisions are made by millions of households and firms acting in their own interest, guided by prices.
• Prices signal scarcity and reward efficient use of resources, so the "invisible hand" (Adam Smith) leads to an efficient allocation of what, how and for whom to produce.
• Competition encourages efficiency, innovation, variety and quality.
• Examples: markets for vegetables, mobile phones and clothes work without central planning.

Governments can sometimes improve market outcomes Markets work well only when property rights and rules are enforced. Government intervention can be justified for two reasons:

1. Efficiency, in case of market failure:
   • Externalities, such as pollution, where social cost exceeds private cost. Governments use taxes, regulation or subsidies.
   • Market power, as in a monopoly, which restricts output and raises price. Governments use competition policy and price regulation.
   • Public goods, such as roads and defence, which markets under-provide.
   • Information problems, which need consumer protection and standards.
2. Equity: Markets may produce a very unequal distribution of income. Taxes, subsidies and welfare programmes can redistribute income.

Conclusion. Markets are generally efficient, but not perfect. Government should intervene only when it improves outcomes, because policy can also fail.

Given: $Q_0 = 1000$, $P_0 = \text{Rs } 2000$, $P_1 = \text{Rs } 2200$, $E_d = -1.5$.

Percentage change in price

$\frac{2200 - 2000}{2000} \times 100 = 10\%$

Percentage change in quantity

$\%\Delta Q = E_d \times \%\Delta P = -1.5 \times 10\% = -15\%$

New quantity

$Q_1 = 1000 \times (1 - 0.15) = 850 \text{ jeans}$

Total revenue

$TR_0 = 1000 \times 2000 = \text{Rs } 20{,}00{,}000$

$TR_1 = 850 \times 2200 = \text{Rs } 18{,}70{,}000$

Comment. Total revenue falls by Rs 1,30,000 (6.5%). Because demand is elastic ($|E_d| = 1.5 > 1$), the percentage fall in quantity is larger than the percentage rise in price. The price rise strategy is therefore not advisable if the firm wants to increase revenue. The firm should instead consider lowering the price, though the effect on profit also depends on cost savings from selling fewer jeans.

The cardinal approach (Marshallian utility analysis) assumes that utility can be measured in units (utils) and that the consumer maximises total utility subject to income.

Assumptions: rational consumer, diminishing marginal utility, constant marginal utility of money, given income and prices.

Equilibrium in the multiple-commodity case. With goods $X, Y, \dots, Z$ and a fixed income, the consumer is in equilibrium when the marginal utility per rupee is equalised across all goods and equal to the marginal utility of money:

$\frac{MU_x}{P_x} = \frac{MU_y}{P_y} = \dots = \frac{MU_z}{P_z} = MU_m$

with the budget fully spent: $P_xQ_x + P_yQ_y + \dots = M$.

Derivation of the demand curve for X

1. At the initial price $P_x^0$, equilibrium holds at quantity $Q_x^0$, where $MU_x/P_x^0 = MU_m$.
2. If the price of X falls to $P_x^1$, then $MU_x/P_x^1 > MU_m$. X is now cheaper per util, so the consumer buys more X (substituting it for other goods).
3. As more X is bought, $MU_x$ falls by the law of diminishing marginal utility, until $MU_x/P_x^1 = MU_m$ again at a larger quantity $Q_x^1$.
4. Repeating for other prices gives pairs $(P_x, Q_x)$: lower price, larger quantity.
5. Plotting these pairs gives a downward-sloping demand curve, which is the consumer's $MU_x$ curve scaled by $MU_m$:

$P_x = \frac{MU_x}{MU_m}$

The demand curve slopes downward because marginal utility diminishes. The market demand is the horizontal sum of individual demands.

Examples for a garment firm

Fixed costs:

1. Factory building rent
2. Salaries of permanent managers and supervisors
3. Depreciation of sewing machines
4. Insurance premium
5. Interest on loans and licence fees

Variable costs:

1. Cloth and fabric
2. Thread, buttons, zippers and labels
3. Wages of piece-rate or casual workers
4. Electricity used in production
5. Packaging and transport of goods

The labour demand curve is the marginal revenue product of labour ($MRP_L = MP_L \times P$). It shifts when factors other than the wage change:

1. Change in the price of output: A higher product price raises $MRP_L$ and shifts demand to the right. A lower price shifts it left.
2. Change in labour productivity: Better skills, training, technology or more capital raise $MP_L$ and shift demand right.
3. Change in the price or quantity of other inputs: If capital is complementary to labour, a cheaper capital raises labour demand. If capital is a substitute, cheaper capital reduces labour demand.
4. Change in demand for the product: Greater market demand for the final good increases derived demand for labour.
5. Number of firms or the size of the industry: More firms in the market raise market labour demand.
6. Technology: Labour-saving technology reduces demand. Labour-using technology increases it.
7. Government policy: Taxes, labour laws and subsidies.

A change in the wage rate itself causes only a movement along the curve.

Step 1: Inverse demand and revenue

$Q = 3000 - 0.1P \Rightarrow P = 30000 - 10Q$

$TR = PQ = 30000Q - 10Q^2 \Rightarrow MR = 30000 - 20Q$

Step 2: Marginal cost

$C = 40Q^2 + 5{,}000{,}000 \Rightarrow MC = 80Q$

Step 3: Equilibrium, $MR = MC$

$30000 - 20Q = 80Q \Rightarrow Q = 300$

The second-order condition holds because the slope of MC (80) exceeds the slope of MR (-20).

Step 4: Price

$P = 30000 - 10(300) = \text{Rs } 27{,}000$

Step 5: Profit

$TR = 27000 \times 300 = \text{Rs } 81{,}00{,}000$

$TC = 40(300)^2 + 5{,}000{,}000 = 36{,}00{,}000 + 50{,}00{,}000 = \text{Rs } 86{,}00{,}000$

$\pi = 81{,}00{,}000 - 86{,}00{,}000 = -\text{Rs } 5{,}00{,}000$

Result: equilibrium quantity is 300 units, price is Rs 27,000 and the firm makes a loss of Rs 5,00,000. It still covers its variable cost (the average variable cost, $40Q = \text{Rs } 12{,}000$, is less than the price), so it can continue in the short run.

Having many sellers and many buyers is a feature of both perfect competition and monopolistic competition, so we must compare the other features.

Reasoning. Raw chicken is a similar product, and prices across shops are close. However, perfect competition requires identical products, perfect information and perfect mobility. In Nepal, the sellers (shops, farms, brands such as packaged chicken) differentiate by freshness, hygiene, location, branding, delivery and trust. Customers show preferences, so sellers have some control over price. Prices also vary by locality and season, and there are local sellers' associations. Sellers earn normal profit in the long run because entry is easy, as in monopolistic competition.

Conclusion. The chicken meat market of Nepal is closer to monopolistic competition than to perfect competition, though it shows some competitive features.

Given: $Q = 1000\sqrt{KL} = 1000K^{0.5}L^{0.5}$, $w = 20{,}000$, $r = 45{,}000$, $P = 100$, $C = 18{,}00{,}000$.

Step 1: Marginal products

$MP_L = 500\sqrt{K/L}, \qquad MP_K = 500\sqrt{L/K}$

Step 2: Optimum condition, $MP_L/MP_K = w/r$

$\frac{MP_L}{MP_K} = \frac{K}{L} = \frac{20{,}000}{45{,}000} = \frac{4}{9} \Rightarrow K = \frac{4}{9}L$

Step 3: Budget constraint

$20{,}000L + 45{,}000K = 18{,}00{,}000$

$20{,}000L + 45{,}000 \times \frac{4}{9}L = 20{,}000L + 20{,}000L = 40{,}000L = 18{,}00{,}000$

$L = 45, \qquad K = 20$

Step 4: Output

$Q = 1000\sqrt{20 \times 45} = 1000\sqrt{900} = 1000 \times 30 = 30{,}000 \text{ packets}$

Step 5: Revenue, cost and profit

$TR = 100 \times 30{,}000 = \text{Rs } 30{,}00{,}000$

$TC = \text{Rs } 18{,}00{,}000$

$\pi = 30{,}00{,}000 - 18{,}00{,}000 = \text{Rs } 12{,}00{,}000$

Result: optimum labour 45 units, capital 20 units, output 30,000 packets and profit Rs 12,00,000.

Effect of a subsidy on equilibrium

A per-unit subsidy lowers the producers' cost, so supply increases and the supply curve shifts downward (to the right). At the new equilibrium, the market price paid by consumers falls and the quantity traded rises. The sellers receive the price plus subsidy. The benefit is shared between consumers and producers depending on the elasticities, and the government bears the cost (subsidy per unit times quantity).

Equilibrium before subsidy

$Q_d = Q_s \Rightarrow 750 - 0.5P = 10 + 1.5P$

$740 = 2P \Rightarrow P = \text{Rs } 370$

$Q = 750 - 0.5(370) = 565 \text{ units}$

Equilibrium after a subsidy of Rs 50 per unit

Producers receive $P + 50$ for each unit, so the supply function becomes

$Q_s = 10 + 1.5(P + 50) = 85 + 1.5P$

$750 - 0.5P = 85 + 1.5P \Rightarrow 665 = 2P \Rightarrow P = \text{Rs } 332.50$

$Q = 750 - 0.5(332.5) = 583.75 \text{ units}$

Effects

• Price paid by consumers falls from Rs 370 to Rs 332.50, a fall of Rs 37.50.
• Price received by sellers rises to $332.5 + 50 = \text{Rs } 382.50$, an increase of Rs 12.50.
• Quantity rises from 565 to 583.75 units.
• Cost to government: $50 \times 583.75 = \text{Rs } 29{,}187.50$.
• Consumers get 75% of the subsidy benefit (37.50 of 50) and producers 25%.

Price discrimination means charging different prices to different buyers for the same good, where the price difference is not explained by cost differences.

(a) Degrees of price discrimination

• Kathmandu Publishers (KP): third-degree. It divides the market into two groups, campus libraries (demand 500, price Rs 700) and students through book shops (demand 2000, price Rs 350). Each group pays a different uniform price according to its elasticity. The library group is less elastic, and the student group more elastic.
• ABS, price to students for the book (Rs 400 to Rs 500): first-degree (perfect). The owner identifies each student's willingness to pay and charges that maximum price, so almost all consumer surplus is taken.
• ABS, exercise books: second-degree. The price depends on the quantity bought: Rs 50 for one piece, Rs 250 for six (Rs 41.67 each), and Rs 450 for twelve (Rs 37.50 each). The block price falls as quantity increases.

(b) Conditions for price discrimination

KP and ABS meet the conditions broadly. ABS's pricing of the book also depends on its ability to identify each student's willingness to pay, which is rarely possible in practice.

(c) Effect on profit

KP: revenue with discrimination is $500 \times 700 + 2000 \times 350 = 3{,}50{,}000 + 7{,}00{,}000 = \text{Rs } 10{,}50{,}000$.

With a single price, KP could charge Rs 350 and sell 2500 books for Rs 8,75,000, or charge Rs 700 and sell only 500 books for Rs 3,50,000. Discrimination therefore raises revenue by at least Rs 1,75,000. If marginal cost is the same, profit rises by the same amount.

ABS book: charging each student Rs 400 to Rs 500 captures consumer surplus. A uniform price of Rs 400 would lose the extra amount from those willing to pay up to Rs 500, and a price of Rs 500 would lose the less willing students.

ABS exercise books: a dozen at Rs 450 earns Rs 150 less than 12 single sales at Rs 600, yet it induces customers to buy more, and stock moves faster. If the per-unit margin stays positive, profit rises through volume.

So all these strategies convert consumer surplus into producer surplus and expand sales, which increases profit.

(d) Is it rational? Critical comments

Rational for the firm: it increases profit, serves customers who would not be served at a uniform price (students get cheaper soft-cover books), and allows fixed costs to be recovered. Total output rises toward the competitive level, so it can be more efficient than a single monopoly price.

Criticisms:

• It reduces consumer surplus and can be seen as unfair.
• Perfect discrimination needs information that is hard to get and creates a distrust risk.
• Customers may resell or switch, and the firm may face legal and ethical objections (exploitation of buyers).
• It requires costs of separation and enforcement.

Conclusion: It is rational for a firm with market power when the conditions are met, and it can increase welfare when it expands output to buyers who would otherwise be excluded. But it should be applied fairly and transparently.